An educated guess based on known information
Conjecture
6, 10, 14, 18, ______, _______, ______
22, 26, 30
4, 8, 12, 16, _______, ________
20, 24, 28
Add 4 to each term
If x is any number, then x² is greater than 2.
False
Counterexample: 1²
5, 10, 15, 20, _____, _____, _____
25, 30, 35
Geometric Number Pattern
58, 51, 44, 37, ______, ______, _____
30, 23, 16
7:30, 8:15, 9:00, 9:45, _________, ___________, ___________
10:30, 11:15, 12:00
Add 45 minutes
a+7=12
False
A=8
8+7=15 not 12
3, 9, 27, ____, _____, ____
81, 243, 729
The drawing of conclusions or inferences from known or assumed facts
Reasoning
5, 25, 125, ______, ______, ______
625, 3125, 15625
Angle ABC is a right angle
Conjecture: Angle ABC is equal to 90°
∠1 and ∠2 form a linear pair therefore, ∠1 and ∠2 are supplementary.
True
If you live in Illinois, then you always live in Peoria.
False
Counterexample: You could live in Pekin
1, 4, 9, 16, 25, 36, 49,...
Number Pattern
256, 128, 64, 32, ______, ______, ______
16, 8, 4
Ray BD bisects angle ABC.
Conjecture: Angle ABD is equal to angle DBC
If x²=16, then x=4.
False, x = -4
If ∠1 and ∠2 are supplementary, and ∠3 is equal to ∠ 1 + ∠2, then ∠3=180°.
True
A statement that proves something is not true
Counterexample
½, ¾, 1, 1¼, 1 ½, _____, _____, _____
1 ¾, 2, 2 ¼
∠1 is vertical to ∠2
Conjecture: angle 1 is equal to angle 2
If angle ABC is obtuse, then it is equal to 100°.
False
Counterexample: an angle equal to 145°
A,B,C, J, K, L, A, B, ____, _____, ____
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
C, J, K